The present invention relates generally to medical diagnostic and surgical instruments and, in particular, to an improved laryngoscope including a blade incorporating fiber optic bundles thereon.
A human, like most vertebrates, has a plurality of internal passageways, tracts, tubes or pipes communicating between the mouth and the stomach or the lungs. The pharynx is a tract that extends from the nasal cavities to the larynx. The larynx is the upper part of the respiratory tract between the pharynx and the trachea, having cartilaginous walls and containing vocal cords enveloped in folds of mucous membranes attached to the sides. The trachea is a thin-walled tube of cartilaginous and membraneous tissue communicating between the larynx and the lungs to carry air to and from the lungs. The esophagus is a digestive tract communicating between the pharnyx in the area of the larynx and the stomach to carry food to the stomach.
The esophagus and trachea are positioned side-by-side and terminate in the area of the larynx. Thus, both food and air use the common pharynx between the mouth and the nasal cavities and the larynx area.
To prevent food from entering the larynx, a valve member called the epiglottis is provided on the outlet side of the larynx, just above the vocal cords. The epiglottis is a piece of leaf-like tissue composed of cartilage covered by mucous membrane and functions as a lid to cover the entrance to the larynx or voice organ during the act of swallowing. The mucous membrane of the epiglottis is loose and extends to the root (beginning) of the tongue. In doing so, it forms several folds. One that extends to the mid-line of the tongue is called median glosso epiglottic fold. A fold that goes to the side of the tongue is called the lateral glosso epiglottic fold. Between the median fold just described and the lateral fold, there is a natural depression or groove. This natural depression or groove is called the vallecula epiglottica, vallecula being a generic term for a shallow depression or groove. There is one such vallecula on each side of the median glosso epiglottic fold, i.e., a left and right vallecula.
A laryngoscope is a device that enables one to view into the larynx of a patient. Moreover, the laryngoscope assists in the intubulation or insertion of endoscopes down the trachea or esophagus of a patient by stretching the pharynx or throat sufficiently to permit passage of the endoscope while allowing viewing of the endoscope as it is inserted. Endoscopes are tubular instruments combining a light system and a telescopic system used in the visualization of the interior of a member such as an organ, and are adaptable for diagnostic, therapeutic and surgical procedures.
Laryngoscopes are formed of two main members: a handle member and a blade member. The handle member generally is a cylinder adapted to receive therein, batteries for powering a light source such as a lamp. The handle member includes an attaching or lock portion to which the blade member is operatively attached.
The blade member is generally one of two types: straight or curved. The curved type of a blade member is better suited for persons of normal anatomical configuration while the straight type blade member is better suited for persons with certain abnormally configured larynxes.
Either type of blade member includes a spatula portion and, generally, an upstanding leg portion. Each blade member is elongated and extends from a proximal end attached to the handle member to a distal end which is inserted into the patient's throat.
Laryngoscopy is the visual examination of the exterior and interior of the larynx by means of the laryngoscope. During a laryngoscopy, the blade of the laryngoscope is inserted into the throat or pharynx of the patient and the tip of the distal end of the blade is placed into the vallecula epiglottica, i.e., the depression formed at the base of the tongue and the epiglottis. With slight pressure, the blade causes the epiglottis to lift up, thereby exposing the larynx to the view of the medical professional performing the laryngoscopy.
Several features have been incorporated in the blade members to improve the viewing by the medical professional. On some blade members, the spatula includes a concave portion at the mid-portion to provide a tunnel along the length of the blade member through which the line of sight of the medical professional extends. Furthermore, lamps have been incorporated on some blade members to provide illumination into the interior of the patient's pharynx.
In some instances, the anatomical variations of the human throat are such that even when using a standard curved blade, the vocal cords can lie out of the direct vision line of the medical professional inserting the laryngoscope blade member. Thus, the medical professional will not have a clear view of the vocal cords when inserting the blade of a laryngoscope. This can be critical because the blade can be inserted such that the patient's throat is subject to trauma. Thus, it is highly desirable to provide a medical professional with the ability to view the area adjacent the distal end of a curved laryngoscope blade member so that trauma to the throat of a patient can be avoided.